The sports category has a large fan base, which can number half a billion in a few years.

Companies stand to make lots of money for appealing to this large and growing market.

There is a massive growth opportunity in the realm of competitive video gaming, known as esports, and it could make some well-heeled tech companies even richer.

Esports has a large and engaged following that is under-monetized, Todd Juenger, a Bernstein analyst, said. He believes this could present an attractive revenue opportunity for companies and investors alike.

In the US alone, esports viewership already outnumbers NHL viewers, and its projected to surpass the number of MLB viewers by 2020, Juenger says. Globally, esports draws an active viewership of 143 million, and that number shoots up to 307 million if you count occasional viewers. Juenger expects that number to explode to 250 million active viewers and over half a billion occasional viewers by 2021.

With the rising popularity of esports, some companies are jumping on the bandwagon to appeal to this large and growing segment, Juenger says.

Here are five companies that will likely reap massive profits from the overlooked sport:

Activision

Esports' Impact: Activision Blizzard is one of the biggest beneficiaries of the esports boom thanks to the success of its recently-launched Overwatch League, a professional esports league for the widely popular video game "Overwatch." The league's ascendance has helped catapult the esports category into the mainstream.

There is significant potential to generate revenues and profits from the league via sponsorships, advertising, and media rights, Juenger says. He believes the league's continued success would deliver "many multiples" of cash flow in the long run.

"Overwatch League represents a rare opportunity for public market investors to become equity owners in a professional sports league, at an early stage," Juenger wrote.

Electronic Arts

Esports' Impact: Electronic Arts will likely see the reward from its esports play "over time," as Juenger describes the gaming company's esports approach as more "grassroots." There will be an "incremental monetization opportunity over time," he said, as EA leverages its partnerships with sports leagues, such as FIFA, and TV networks, like Disney, to mutually promote and engage audiences at sports events, as well as their respective video games.

Nvidia

Esports' Impact: While the cryptocurrency rush has propped up the chipmaker's shares, gaming still makes up over 50% of Nvidia's business. That business has grown 33% over the past few years, Juenger notes. There are some long-term, secular trends that are driving the gaming market and demand for the highly sought-after chips will not dissipate soon, he says.

"We see the engagement levels around this trend as having the potential to both bring new users into the installed base, particularly new users that are young and of relatively high income," Juenger wrote.

Microsoft

Esports' Impact: Microsoft has seen gaming and "mixed reality" — which blends virtual reality with real life — as one of its growth opportunities. The tech company is making a play on the esports market through a combination of acquisitions, such as Beam and PlayFab, as well as internal "organic" development.

The company has built esports studios within its physical stores and has run its own esports competitions. With the use of its Azure cloud platform, gaming software and hardware, and mixed reality push, it can be a "major player in the market," Juenger says.

The company's planned Mixed Reality Headsets should also serve as a catalyst for Microsoft's Windows platform and Xbox businesses while also driving revenue and profits.

Sony

Esports' Impact: Sony's PlayStation 4 has some of the biggest esports names, such as Street Fighter V and Gran Turismo Sport. The company is making a hard pivot toward esports by partnering with competitive-gaming event producer ESL and launching its own PlayStation tournaments.

Juenger sees an opportunity for Sony to synergize its TV channel, new programs, and PlayStation Vue around esports.